Microarray readers conventionally used are based on florescent label, confocal microscopy and evanescent field. Examples include florescent scanning confocal microscopy and total internal reflection (TIR) fluorescent microscopy. These readers have a small field of view and require precise moving parts to scan the array, which leads to costly and slow reading. One approach includes exciting the whole probe array by expanding light source with uniform intensity distribution. However, lower sensitivity results due to the lower excitation.
Microarray readers with waveguide structures can produce high sensitivity and are free of moving parts. These readers are not suitable for disposable chip applications though, because of the high costs of waveguide fabrication and rigid alignment and coupling requirements. None of the existing microarray readers can meet the need of real-time PCR microarray detection due to the unique requirements in temperature control and sampling synchronization.